"Compounds endowed with a juvenile hormonic activity" or briefly "juvenile hormones" are terms which indicate, whenever used in the present description, those compounds which, although not being natural juvenile hormones of the insects, possess nevertheless analogous characteristics thereof.
When these compounds come into contact with juvenile forms of insects such as, e.g., larvae or neanids or even embryos in the egg, they are capable of affecting the development of the insect depending on the time and on the administered dose, also causing, depending on the species, the death of the individual insect or serious malformations leading to the death or to individuals unable to reproduce.
Also in applications to adult forms, these compounds may prove to be active in preventing the insect reproduction by inhibiting the oviposition or the hatching of the eggs.
The use of compounds endowed with a juvenile hormonic activity offers considerable ecological advantages as compared with the conventional insecticides; in fact, the juvenile hormones are highly selective, wherefore they do not damage the useful species and, above all, are little toxic towards warm-blooded animals and fish.
Several compounds exerting a juvenile hormonic activity are known, such as the ones described in U.S. Pat. Nos. 4,061,683; 4,141,921 and 4,153,731 (Ciba Geigy), in British patent application No. 2,023,591 and in U.S. Pat. No. 4,126,623 (Montedison S.p.A.).